Stereoinvertive C–C Bond Formation at the Boron‐Bound Stereogenic Centers through Copper‐Bipyridine‐Catalyzed Intramolecular Coupling of α‐Aminobenzylboronic Esters

Abstract

Enantiospecific intramolecular Suzuki–Miyaura‐type coupling with α‐(2‐halobenzoylamino)benzylboronic esters to give 3‐substituted isoindolinones is achieved by using copper catalysts with 2,2′‐bipyridine‐based achiral ligands. Enantioenriched α‐aminobenzylboron reactants bearing a hydrogen atom at the boron‐bound stereogenic carbons undergo stereoinvertive coupling in the presence of a 6‐phenyl‐2,2′‐bipyridine ligand with high enantiospecificity. α‐Aminobenzylboronates bearing fully substituted boron‐bound stereogenic centers also gave the 3,3‐disubstituted isoindolinones with stereospecific stereochemical inversion in the presence of simple 2,2′‐bipyridine as a ligand.